What's new
  • Please note members who been with us for more than 10 years have been upgraded to "Veteran" status and will receive exclusive benefits. If you wish to find out more about this or support IcMag and get same benefits, check this thread here.
  • Important notice: ICMag's T.O.U. has been updated. Please review it here. For your convenience, it is also available in the main forum menu, under 'Quick Links"!

Sealed dep greenhouse

Speed of green

Active member
Whats up icmag, This greenhouse was built on the lowest budget possible and is a prototype to test a few theories before i take things full scale.

First thing's first, this greenhouse is located in a heavily populated area, my neighbors aren't really cool with weed, there is also an ordinance in my city banning outdoor cultivation, the greenhouse un-permited I'm sure in violation of some code.

My goals are to be able to grow year round, i want to be able to harvest 4 times a year. i also have to contain the smell.

THE STRUCTURE
25x15x7.5

2x4's pvc and wiggle wire. very simple and cheap construction, it took one weekend to build.

the greenhouse is air tight, on one end there are 3x 12" canmax fans 1700cfm each. there are also three 6' carbon filters.

on the opposite end of the carbon filters there are 2x 20x30 house filters that act as passive intakes.

with just one fan running there is plenty of negative pressure and hopefully i will be able to control all the smell.

the temperature stays within 2deg of the outside temp with one fan running, i expect on the hotter days i will have to run all three fans to maintain the ambient temperature.

My main worry at this point is if the carbon filters will fail under humid conditions.

the greenhouse has already survived a ver strong windy storm and seems to be anchored properly.

The greenhouse plastic is 60% diffused plastic, it is translucent.

the dep tarp is 12mil reinforced poly.


The plants.

50 blue dream
30 backwater OG
3 gorilla glue
3 mendo breath
3 girl scout cookies
3 training day
3 cherry pie
3 xxx OG

the plants are all in 2 gallon pots
promix HP is the medium, Im hoping the plants won't get root bound in these small pots. my goal is 1/4-1/2lb per plant.

100 GPD R/O

Jacks 5-12-26
Calcium nitrate 15-0-0
PEKacid (drip clean)

Right now I'm feeding with every watering with runoff.

ph is 6.1-6.3 This may be a little low for promix, Any suggestions?
ec 1.2-1.4

i use a milwaukee TDS PH combo along with a truncheon, and a bluelab PH pen to double check all my values and make sure i don't make stupid mistakes. having both meters reading the same ph and ec values gives me a lot more confidence.


The plan is to set everything up on a drip system and trellis the entire greenhouse, hopefully the plants will be trained/pruned well enough that they won't need much assistance once they grow through the trellising.



Any input is appreciated.

Thanks.

 

HillMizer

Member
It's not fully sealed and you're in Socal so I don't think you'll have humidity issues during the normal season.

It's probably still going to get really effing hot. The cover being only 60% transmission should help. I would consider adding carefully monitored evaporative cooling if you plan on running this summer.

I hope you can hit your goals of 1/4- 1/2 lb per plant but it sounds high for that size container, 2 gallons are going to want to dry out. I suggest at least 5 real gallons. I often use a 30 gallon to get those types of numbers. It just sucks to over estimate yield.

I would say anywhere from .5 to 1.2 oz per square foot of canopy is a good estimate. 1.2 is REALLY crushing and .5 means you really need audit your systems. 11-30 lbs. Hopefully about 20lb if you FILL that thing.

Good luck!
 

Lester Beans

Frequent Flyer
Veteran
First thing's first, this greenhouse is located in a heavily populated area, my neighbors aren't really cool with weed, there is also an ordinance in my city banning outdoor cultivation, the greenhouse un-permited I'm sure in violation oF some code...

So how do you plan to deal with city inspectors or neighbors? Seems awful sketchy to me. Aren't you afraid the city will stop by and ask to see your permit for the structure or neighbors may get curious or blow you in?
 

HillMizer

Member
First thing's first, this greenhouse is located in a heavily populated area, my neighbors aren't really cool with weed, there is also an ordinance in my city banning outdoor cultivation, the greenhouse un-permited I'm sure in violation oF some code...

So how do you plan to deal with city inspectors or neighbors? Seems awful sketchy to me. Aren't you afraid the city will stop by and ask to see your permit for the structure or neighbors may get curious or blow you in?

No concrete, no permanent wiring , no permanent plumbing. It's small, it's a temporary structure. Cross your fingers, keep it neat,have your paperwork & legal representation in order, bring your neighbors cookies and don't have parties or anything to draw attention. There's usually bigger fish to fry, in CA anyway. I've been violating ordinances my whole life.
 

Speed of green

Active member
I have (3) 1700 cfm fans = 5100 cfm - by the time i put ducting and carbon filters on these fans... I'm probably looking at 3000 cfm MAX.

the greenhouse is 2700 cubic feet. so i should be able to exchange the air 1x per minute, while filtering all smells.

i would totally do a swamp cooler, but the greenhouse is literally right on the ocean so its not dry enough.

I've already had a 77 degree day and the greenhouse was at 80 mid-day with only one fan running, i think with the air exchange 1x per minute ill be able to match the outdoor temperature.

The hottest it gets here (san clemente) is a week of 90 degree weather, most of summer it stays in the 80's, worst case scenario i have to open up the sides during the hottest parts of the day.

I talked to my neighbors and even and showed them my scripts, they understand its all legal and that they won't be able to see/smell anything, i feel like they are receptive to the idea, like i said this is a trial run to see what happens. if it smells and my neighbors have a problem then i told them to come to me first and i would do everything in my power to fix the situation, including cutting the plants down.

I have no experience with promix, from my understanding it can be used like a hydro medium or a soil medium depending on how you treat it. the drip setup will be able to do multi-feeds daily like coco, I've seen one pound plants come from 1 gal coco pots fed 5x a day. i understand that this isn't coco though, possibly next run ill try that if i can't get the yield i want from this promix.

I realize its damn near impossible that we will pull 50lbs from this tiny greenhouse. realistically i think 20 would be cool, any more than that and we are stoked.

The main reason i decided to do this grow is because i was planning on throwing 12 DE setups in the garage with a 5ton ac. instead of putting 15k into that venture we decided fuck it lets run a $1500 greenhouse and see what happens. if we pull one harvest the ROI is killer.
 

Speed of green

Active member
picture.php
picture.php



The plants are all about 30" tall, they have been topped once, ill probably top them one more time and start flowering in 1-2 weeks, whenever the plants fill in the trellising.

I wouldn't consider the greenhouse a beautiful structure, but i don't think its an eyesore either. everything is clean and tidy, no parties, i think everything should be fine as long as the smell is contained.
 

HillMizer

Member
Looks and sounds good. You might do pretty well with the coastal weather. You got this.
I'd transplant those if it were me. If you're gonna set em up to water multiple times per day and treat it like hydro then maybe it's fine.
Good work!
 

Lester Beans

Frequent Flyer
Veteran
One pound plant from one gallon of coco??? I'd have to see that to believe it.

Sounds like you have a solid plan! Nice greenhouse BTW! Good luck with your grow!
 

JJ Lowe

Active member
I live in socal coastal as well. I built a shed 120 sq ft. with a solexx greenhouse top, works great in the winter and early spring months. I tried scrubbing and exhausting like you and the fans just couldn't keep up in the summer. Have you looked at the heat activated vent arms? I ended up adding a 24k btu window shaker with co2. Power bill went up around 500$ in the summer.. I ended up taking everything indoors with Lec's.
Good call on the jacks.. some good stuff..
The BD worked the best me as they seem to tolerate the fluctuations in temps and humidity well.
Good luck!
 

CrushnYuba

Active member
Your summers will be hard but anything's possible. I have tried similar projects.
12" inline fans suck for greenhouses in the summer. They will do a good job in winter and they will keep it ventilated during black out, but when the sun is shining, they are almost useless in summer.

If you really want to make this work, in the summer, Use thick shade cloth. Like 60%++ at least.
Also, you are going to find out real quick that having intake on one side and exhaust on the other, won't work. The intake side will be ok but by the time you get to the end, you are screwed. Move your exhausts to be evenly spaced on the roof. One on each end and one in the middle. Make your intakes evenly spaced at the floor boards. The sun is just to much and the end furthest from your intake is just going to be to hot with how you have it now. Solar gain is a bitch.
With your humidity, you need butt loads of directional air movement fans running a loop. Summer or winter. Only way to keep rot and disease away.
I would lay down white plastic on the floors. Try to reflect some heat out.
Are your days in summer humid when the sun is out? If they aren't that bad, it could be a game changer and we can talk cheap evaporative cooling.
You can't trellis the whole greenhouse. Especially with your humidity. You need rows.

Not trying to be negative. Just trying to help. I think it's cool what you are doing. I'm just trying to take some of the trial and error out of it. I tried the same thing. I did it with basically a big shed covered with rigid polycarbonate. I have lower humidity so evap cooling works well. Spring was great. Summers were really really hard. I live off grid so I can't do indoor. I have to run greenhouses.
 

HillMizer

Member
You can trellis the whole greenhouse with irrigation but you have to have it high enough to crawl and cut holes to pop through and spray and inspect.
I did it this way for years, pathogens (esp. Mites!) spread fast though. High canopy temperatures make spider mites a big problem too.
It'll work out! You'll find a way that works best for you.
 

CrushnYuba

Active member
Yea. Crawling on the ground under trellis is brutal. The thing is 15ft wide. With the humidity you are talking about, you are going to have to be vigilant with checking for molds and pests. You need to know the very second you have a rot spot and it needs to be treated. Mold and mites spreads in greenhouses fast that aren't coastal.

I think what you are doing is really rad and I give you props. Please keep this thing going. See no evil, smell no evil. This would open some doors for people in more suburban areas. Maybe share it with the indoor forum. I bet there are allot of indoor growers in high humidity areas using carbon filters. I have always dreamt of being in a place you can flower outside year round. Up here, we just don't have the light in winter and it basically turns into an indoor.
 

Speed of green

Active member
had all three fans running today, its like a wind tunnel in there, i think i have the airflow sorted for now. it was 76 at the hottest part of the day and the gh stayed 80deg 40% humidity.

At what temp / RH should i be in panic mode, i know it gets over 100 in Nc/grass valley.

My black 12mil tarp comes monday, I'm stoked to get everything in its final spot, hopefully start flowering in a week or so. Plants are growing very fast 1-2" per day it seems like.

for my preventative i have hit them with eagle20, forbid4f, floramite all when they were clones. I'm going to re apply eagle20, forbid and avid right before flower. I hate to use these products but crop failure almost certain without them.

I foliar fed with fulvic acid 1tbsp/gal and epsom 1.5tsp/gal a couple days ago, they are really stoked on that, leaves pointing straight up, tracking the sun all day.

i know I'm going to be army crawling through this thing once a week minimum, I'm not looking forward to it but a sacrifice that has to be made. at least there is a weed barrier so I'm not directly on the dirt.

The sun is powerful here, I'm really impressed with the growth rates I was seeing in February, i think year round light dep with some supplemental is totally possible, i think yield and potency may suffer slightly but overall i think its doable.


Thanks for the support! ill keep this updated. Also did ICMAG change the resolution on photo uploads? All my recent pictures look like shit, i know i took them on an iPhone but normally they are much better quality.
 

CrushnYuba

Active member
Not really sure when you should start panicking with temperatures. Grass valley is regularly over 90 and my plants rage. The real heat waves they slow down growing real bad. Your humidity makes it different. You should research vapor pressure deficit. High heat WITH high humidity can give you amazing growth rates. Find a vpd chart and im sure there are threads. Your conditions are ideal right now.
I use those toxic chemicals. People talk smack but I rather use it early on and prevent problems then use it to close to flowering because I had a problem... I would also use something for bud rot also because of your humidity. I use Forge SP or actinovate. It's organic and odorless and you can use it through flowering.
Bayer makes a new fungicide that can replace your eagle 20 for PM and it will also work as a systemic fungicide against bud rot. I have always wanted to try it but I don't really get much rot to try it with. As far as I know it's the only systemic that works against bud rot. It's also supposed to be safer then eagle 20.

1-2" a day is killing it. You will crush it in flower. Up here fall and spring runs potency and bag appeal go up. It straight looks like indoor. You just take a hit in yield.
 

maxmurder

Member
Veteran
speed of green- nice thread thanks for sharin.

3 things pop into my head having just read this..

1- have you gotten much rain? the reason I ask is, your flat roof, I see you have support running down the middle but I think any heavy rain might collect and cause some major sagging in between your bows and maybe worse case rip your skin and soak plants, lights, fans etc.

2- you said your neighbors are semi cool but those 12" can fans run max rpms to get that 1700 cfm and the one I had was loud as fuck even with a massive filter and 20' of insulated ducting with a big ass gradual "u" shape, hearing 3 of those kicking on and off all night might bum the neighbors out especially x 3.

3- you said your black cover, is it white and black? that's what you want, white exposed to the sun and black on the inside. if you use just black your plants will be bummed under any direct sun, huge difference...
 
Top